This invention relates to space heaters in general, and to triangularly shaped space heaters with shaped insulation to increase the efficiency and uniformity of heat distribution from such elements in particular.
Certain types of space heating situations require a uniform distribution of heat in those areas to be heated. Particularly is this true in greenhouses where any non-uniformity in heating is manifested by uneven growth of plants or even damage or death to some plants. This is most evident in greenhouses using round tubing through which burning gases are directed as the energy source, where the plants directly under the extended tubing will reveal a higher than normal number of yellowing leaves, and have a higher than normal number of dead and dying plants. Many growers have solved this problem by placing walkways under the heating elements, thus reducing the number of plants exposed to the greater heat. However, this arrangement may not be the most efficient arrangement of plants for the space. Other growers have installed the heating elements over existing walkways, which may not give the most effective distribution of heat.
Several existing space heating arrangements have used a shaped reflector to obtain a more even distribution of heat, as exemplified by U.S. Pat. No. 4,319,125. Other existing space heating devices have used triangular reflectors to direct the heat in a desired direction, of which U.S. Pat. No. 3,604,894 is exemplary. U.S. Pat. No. 3,731,055, on the other hand, discloses a triangularly shaped shield to decrease the amount of heat received by the area directly opposite the heating element. U.S. Pat. No. 2,598,602 discloses a triangularly shaped heating element with an apex facing in the direction to be heated, for the reason that it provides a more uniform distribution of heat. He also discloses a multiplicity of such elements, themselves arranged in a triangular array, with the array mounted vertically, so that a uniform beam of heat will be directed into the space to be heated. Nowhere is the idea expressed, or even hinted at, that a single element could be extended and used to obtain a uniform distribution of heat directly in front of, and on either side of, the element. Finally, U.S. Pat. No. 3,052,789 discloses a triangularly shaped element with insulation applied to the sides of the element, opposite to the direction in which the heat is to be directed. However, this latter disclosure shows the heat being directed from a flat side of the triangular shape and insulates the other two sides to prevent heat loss in those two directions.
None of the above mentioned disclosures would be adequate to solve the problem at hand, that of providing a uniform distribution of heat in a greenhouse in such a way that none of the plants receives too much heat and is thus damaged or destroyed. In fact, several of these disclosures have that very problem when used under such circumstances.